Improvement in oscillating steam-engines



I UNITED STATES FRANCIS MURGATROYD, OF CLEVELAND, OHIO.

IMPROVEMENT IN OSCILLLATING STEAM-ENGINES.

Specication forming part of Letters Patent No. 34,161, dated January 14, 1862.

To a/ZZ whom, it may concern:

Be it known that I, FRANCIS MURGATROYD, of Cleveland, in the county of Cuyahoga and State of Ohio,have invented new and useful Improvements in Steam-Engines; and I do hereby declare that the following is a full and complete description of the construction and operation of the same, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a front View. Fig. 2 is a side view. Fig. 3 is a top View, and Figs. 4, 5, 6, 7, l8, and 9 are sections; and Fig. 10 is a top view of a completed engine.

Like letters refer to like parts.

The nature of my invention consists in constructing and applying a reversible disk valve and seat to steam-engines which will open two ports to steam and two to exhaust, at the same time forming a more effectual opening for steam to the piston and a more free eX- haust, my method allowing the valve to be made smaller in oscillating engines, the trunnions also smaller, thereby reducing friction.

In my improvement the engine is operated and controlled by a lever as with the usual starting-bar. l

This improvement may be applied with equal advantage to a stationary as well as to an oscillating engine.

In operating steam-engines it is of the greatest importance that the steam be delivered in a full and effective volume immediately after passing the centers, and in the disk-valve the size of the openings is governed by the amount of vibration. It is also important that the valve be made as small as possible consistent with the required steam -openings, thereby reducing the steam-pressure on the valve and thus reducing' the friction.

In the accompanying drawings I have represented the front half of an oscillating engine, except in Fig. 10, which is a top view of the whole engine, showing both the trunnions and the trunnion-plates. The sectional views, however, fully represent those parts involved in my improvement.

A is the cylinder.

B is the piston-rod, and C is the crank.

D is the front trunnion, and E is the trunnien-plate.

F is the steam-port, connected with the upper end of the cylinder, and G is the port connected with the lower end of the cylinder.

H is the steam-chest, in which the valves are situated.

I is the steam-pipe, leading from the boiler to the steam-chest H, and K is the dischargepipe for the exhaust-steam.

D, Fig. 5,is a vertical section of the steamtrunnion, and D is an end view of the same.

Fig. 6 is the face of the valve-seat, which is attached to D', Fig. 5.

Figs. S and 9 show the under side of the valve-seat, and as this seat is attached to the trunnion in oscillating engines it has the same oscillating motion of the cylinder. An approximation to this oscillation is shown by the red lines .fr m y y in Figs. 8 and 9.

The valve-seat is seen in section, Fig. 4, at M M. At N N in the same figure is seen the valve resting upon its seat M.

The valve-stem is shown at C.

Fig. 7 is the under side of the valve. This rests upon its seat, Fig. 6, in the position indicated by a a b b. In this position the engine is on the dead-center, as in Fig. l, the line Z Z in Figs. 8 and 9 representing the p0- sition of the valves. (Shown also in Figs. 6 and 7.)

s s, Fig. 7, represent the steam-ports, and these are opened and closed alternately as the crank-pin C passes the dead-center, and c e are exhaust-ports. VWhen it passes thelower dead-center, the port G receives steam, and when it passes the upper dead-center the port F receives steam.

At L is shown a crank, which moves the connecting-rod M and rock-shaft N thus connecting through O to the arm P, which is secured to the outer end of the valve-stem O, and thus giving more or less motion to the valve, which motion is dependent upon the position of the set-screw P', no motion being communicated to the valve when the set-screw P is on a line with the center of the rockshaft N.

When the eccentric motion L is not in use and the crank-pin is on the dead-center, all the ports are closed.

The eccentric motion is used to give the valve lead by means of the rock-shaft P and crank L while the piston-crank is passing the e e, so as to open two ports to steam and two dead-center, and serves also the purposes of to exhaust at the same time.

a cut-off.

An oscillating engine is reversible by changing the valves by means of changing the 1ever O from i to i', and vice Versa.

What- I claim as my improvement, and desire to secure by Letters Patent, is-` 1. The combination of the openingsssand 2. The valve, Fig. 7, in combination with the reversing-lever O", by means of which the engine can be reversed at pleasure, as specified.

F. MURGATROYD. Witnesses:

J. BRAINERD, W. H. BURRIDGE. 

